Question: Simplify the following expression: $\sqrt{80}+\sqrt{20}-\sqrt{5}$
First, try to factor any perfect squares out of the radicals. $= \sqrt{80}+\sqrt{20}-\sqrt{5}$ $= \sqrt{16 \cdot 5}+\sqrt{4 \cdot 5}-\sqrt{5}$ Separate the radicals and simplify. $= \sqrt{16} \cdot \sqrt{5}+\sqrt{4} \cdot \sqrt{5}-\sqrt{5}$ $= 4\sqrt{5}+2\sqrt{5}-\sqrt{5}$ Finally, simplify by combining the terms. $= ( 4 + 2 - 1 )\sqrt{5} = 5\sqrt{5}$